def caesar_decrypt(ciphertext, shift):
    decrypted_text = ""
    for char in ciphertext:
        if char.isalpha():  # 只处理字母字符
            shift_amount = shift % 26  # 确保移位在0-25之间
            if char.islower():  # 处理小写字母
                decrypted_char = chr(((ord(char) - ord('a') - shift_amount) % 26) + ord('a'))
            else:  # 处理大写字母
                # decrypted_char = chr(((ord(char) - ord('A') - shift_amount) % 26) + ord('A'))
                decrypted_char = char
            decrypted_text += decrypted_char
        else:
            decrypted_text += char  # 非字母字符不变
    return decrypted_text

# 加密段
ciphertext = "Hefu yi jxu jxydw myjx vuqjxuhi ro Ecybo Dysaydied. Hefu yi jxu jxydw myjx vuqjxuhi, Txqj fuhsxui yd jxu iekb, Adt iydwi jxu jkdu myjxekj jxu mehti, Adt duluh ijefi qj qbb, Adt imuujuij yd jxu wqbu yi xuqht; Adt iehu ckij ru jxu ijehc, Txqj sekbt qrqix jxu byjjbu ryht Txqj aufj ie cqdo mqhc. I xqlu xuqht yj yd jxu sxybbuij bqdt, Adt ed jxu ijhqdwuij iuq; Yuj, duluh, yd unjhucyjo, Ij qiaut q shkcr ev cu."

if __name__ == '__main__':
    for i in range(20):
        decrypted_text = caesar_decrypt(ciphertext, i)
        print(f"shift = {i}: {decrypted_text}\n")